156 SYNOPSIS of British seaweeds. 



Hah. On rocfcfl and woodwork, near low-water mark, mostly in 

 deep rock-pools ; sometimes dredged in from 1-7 fathoms. 

 Bather rare, but found all round the coast. Annual. 

 Summer. 

 This plant is common on the shores of France, and in 

 the Mediterranean, where its different varieties, as I re- 

 gard them, are ennobled to the rank of species by most 

 Continental botanists. Among the many forms which this 

 plant puts on, I possess one gathered by Mr. Kalfs at Sal- 

 combe, which is remarkable for extremely squarrose ramuli 

 and spreading branches. 



271. Rothii (Roth's Callithamnion) ; widely spreading, densely 

 tufted ; filaments very slender, short, erect, dichotomous or 

 irregularly branched ; branches long, straight, appressed ; 

 articulations twice as long as broad ; tetraspores clustered, 

 borne on short, subterminal, corymbose ramuli, Lyngh. 11 ml. 

 Dan. p. 129. t. 11. (Atlas, PI. LX. Fig. 278.) 

 Ceramium Rothii, Berk. Trentepolilia Rothii, Harv. Conferya 

 Rothii, Linn. C. violacea, Roth. Trentepolilia purpurea, 

 Ag. Byssus purpurea, JE. Bot. Conferya purpurea, Dillw. 

 Hah. Spreading oyer the surface of rocks, about half-tide leyel. 

 Perennial. Winter. 

 A smaller and more slender plant than the following, 

 with shorter joints, and well characterized by the difference 

 in fructification. I have ventured, I trust not without suf- 

 ficient warrant, to unite to C. Rothii the old Conferva or 

 Byssus purpurea, which I have long regarded as a stunted 

 form, whose characters depend on the situation in which it 

 is found growing. 



275. floridulum {The gay CaUithamnion); tufts yery dense, 

 more or less globose, fastigiate ; filaments slender, dichoto- 

 mous or alternately branched, the branches few, very erect 

 or appressed, long, simple, straight ; articulations thrice as 

 long as broad, cylindrical ; tetraspores oyal, borne on very 

 short, erect pedicels, ranged in a secund manner along the 

 upper branches, Ag. Sp. A Ig. v. 2. p. 188. (Atlas, PI. LIX. 

 Fig. 277.) 

 Trentepolilia floridula, Harv. Conferya floridula, Dillw. 

 Hob. On sand-covered rocks, near low-water mark, at all seasons. 

 Perennial ? March and April. 

 An exceedingly abundant species on the west coast of 

 Ireland, covering a large extent of rock with its hemi- 

 spherical, densely-matted, and aggregated cushions. At 

 the close of summer great quantities of these, which are 



